Locking-switch.



E. 0. SESSIONS.

' LOCKING SWITCH. y l APPUCATIONFILEDwww4,1915.

Patented Jan. 30,1917.

3 SHEETS-SHEET 2.

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E. 0. SESSIONS.

LOCKING SWITCH.

APPLICATION FILED IuNE I4, 1915.

Patented Jan. 30,

3 SHEETS-SHEET 3.

'Il/@J0 tltllillllllltalllt .ai anco.

` pecication of Letters Patent'.

Patented dan. Fllt ttltl.

.application filed .Tune 1li, 1915. Serial ltTo. 33,926.

.cuits whore 'it is desirable to install 'the switch in places not accessible to the-'operator without the use ot some special tooljor device for reaching the switch so that the switch and its associated pa'rtsmay not be accidentally touched by the person ot the operator, thus endangering his lite and safety. Complicated devices have loeenproposed in the past :tor accomplishing the lock-f ing of switches of this hind in their closed position, anden account oit the many parts involved in the locking mechanism these devices have not given unqualilied satisfaction..

lt is an object ol the present invention to reduce the locking mechanism to the fewest number yot parts pomible, thus making the device positive, both in its locking and unlocking operations, andy furthermore, to secure a strength of construction amply adequate to meet all'demands that may be made upon the locking device. This construction is, furthermore, chatacterized by locating the locking parts .outside oit the main path of the current flow so that little or no current flows through the loclr itsellt,'thiis insuring the loclr against the detrimental ettect of heating and arcing.

The several drawings illustrating myl invvention are as follows:

Figure 1 shows a doulole-throw` switch constructed in accordance with :my invention; Fig. Q shows in a vertical sectional View through the lock casing the lock mechanism employed in the form.v of switch shown in Fig. 1; Fig. 3 is a sectional view ot the parts shown in Fig. 2 taken along the line 3-3;-Fig. 4t is a sectional view ot' the-parts shown in Fig. 2, taken along the line lfd; Fig. 5 shows in view similar to FigxQ a form ot locking mechanism toi-'a single-throw switch; Fig. 6 is a sectional view of the parts shown in Fig. 5, taken along the line 6 6; Fig. 7 shows in a view similar to Fig. a modified form of locking mechanism :for a single-throw switch; Fig. 8 shows a portion Aot an oper# ating device tor operating the loch and switchg Fig. 9 shows iny al view similar vto Fig. 1 my locking mechanism as used in con# nectio-n with highftension fuses; 10 shows in a view similarto Fig. 7 a modiheol Construction of lock in which a helical spring is employed instead ot a flat spring; Fig. 11 shows in view similar to Fig. 10 a modiiedconstruction in' which the spring is differently applied; and Fig. 12 shows in a View .similar to Fig. 2 a modihed loclr con struction in which a helical spring is employed to hold the double latch in operative position..y

xSimilar numerals reiter tosirnilar parts 4throughout the several views.

is shown in Figs. l, 2, 3 and 4l, the switch consists of a switch blade 10 pivotally mounted at 11 between connecting jaws 12 forming one terminal ot a circuit. Fhe vswitch jaws 18 and the switch jaws 1d are supportedfrom the same insulating mounting plate 15 as the jaws 12, to be engaged by the switch blade 10 when in one or the other of its circuit-closing positions. lt is immaterial to the present invention what the particular form of mounting ot the switcli" blades may be and whether they have individual or common insulating devices tor properly insulating them from surrounding objects, depending upon the voltage em ployed in the circuit controlled by the switch.

As shown `in Figs. 2, 3 and t, the switch blade 10 has secured by rivets or equivalent tastening devices 16 a housing 1.7 projecting trom the end ot the switch blade, which housing has -pivotally supported therein upon a transverserool 18 two latches 19 and 20, each being in the general term of a bell crank lever. These latches are oit reduced thickness adjacenttofthe pivot rod 18, and their inner ends 19 and 20 where they do not come in contact with each other are of a width substantially equal to the distance between the'opposite walls et" the caeing 17. l slotQl is formed through each ot these opposite walls ot the vcasing 17 and beyond the normal position oli the ends 19um and 20 of the latches to erinit one or the other oit the latches as desired to be engaged' by any convenient operating tool, as, iter er.-

ample, that shown in Fig. 8, by inserting theloentrnetall end 22 'carried by the insulating rod Q3 ot the operating tool, as aresult of which the loch and switch may be operated in a manner to be described.

The outwardly-extending end ot each ot the latches 19 and 2O has formed thereon a hook 19b and 20h ifor engaging a corresponding catch 2t or 25, according to whether the switch blade is in engagement with the contact jaws 1B or 14, respectively. The catch 24 is o'f substantially the same thickness as the switch blade 10, and is secured in the bottom of the groove between the contact jaws 13 by means of screws Q6 which pass through elongated slots Vin the catch 2L so that the catch may be moved longitudinally between the contact jaws 13 to properly engage the latch 19. The catch 25 is similarly mounted between the contact jaws 11- and adjusted to engage the latch 20.

Both of the latches 19 and 20 are noi'- Inally held in a position to engage the cor responding catches by a spring? bent near its middle portion to engage a rib Q8 project-ing inwardly from the wall of the casing so that'displacement ot the spring in the casing is prevented. rThe latches and l2() are held in proper engaging position against the action of the spring 27 by oiset portions 19C and'QOC, which normally rest "against the end of the switch blade 10. The

engaging surfaces of the catches 21 and 25 and the hooks 19b `and 20b are rounded, as

indicated, to lreadily movethe latches against the action of the spring 27 so that the hooks may clear the locking points ot the catches when the switch blade is being moved to its closed position in either the contact jaws 13 or 14.

On account of the comparatively small amount of room afforded in the housing 17 vbythe thickness of the switch blade 10, and

since it is desirable to mount both of the latches upon the saine rod 18, I prefer toemploy .the construction indicated in Fig. 3 in order to atlord a maximum bearing surface for each latch in connection with said pivot rod. In -the construction shown, the latch 19 is provided with a comparatively lthin'hub` 19d projecting from its yinner tace around the pin 18, the amount of this'projection being some distance past the center `line of the housing, and the latch is counterbored and provided with a -tubular flange 20,'which has a sliding fit with the outer cylindrical surface of the hub 19d so that the latch 2O is 'supported uponV the hub 19d as Well as upon the rod 18. In this `way a considerable bearing surface is provided for each latch, and as the end portions of each latch are of practically the thickness 'of the spacebetween the walls of'the housing, there is practically no opportunity for displacement of either latch in the housing ins due to Wear ofthe parts.

l`With the construction ,of the housing 1T.

described, when the switch blade 10 is in the position indin cated in Figs. 1. and 2, the latch lll engaging the catch 2-1. positively holds the switch blade between the jaws 123, thus insuring that the switch blade cannot be accidentally moved troni engagement with said jaws. Furthermore, since the rod 18 is located substantially in line with the locking taces of the hoolis 19 and 20, it is impossible to disengage the latches troni their catches by pulling on the .switch blade or the outside lllhcn it is desired to operate the lock so as to move the switch blade trein the position shown in Figs. 1 and 2, the operating tool (which may have either the construction shown in Fig. 8, or any convenient construction) is inserted through the 4slot Q1 in the housing and pulled downward. rllhis pull lirst engages the end 19= of the latch 151. moving the latch against the action ot the spring .27 upon the pivot rod 1S to disengage the hook 19h from the catch 24, and when this is accomplished the operating device engiges the p ends ot' the slots 21, and a continued pull on the operating device is connnunicatnal directly to the housing 17 and moves the switch blade trom engage 'it with the contact jaws 13. lf it is de. red to leave the switch in its open position. the operating device may be removed when 'the switch blade is moved to a position substantially midway between the contact jaws 13 and 11. li", however, it is desired to close the switch in its reversed position. the motion of the switch blade 10 is continuedy by means ot the operating device. and as the direction of motion is now upward against the latch 19, in moving the Contact blade intp engagement-'with the contact jaws 1l the latch 20 `is free to engage the catch under the action ot the spring` 27. atter which the operat-ing` device is removed.

In the modified construction shown in Figs. 5 and G the switch ot the singlethrow type, and tor this construction the. switch blade 10 has secured to its tree end .the housing 1T similar to the housing l? described above, the principal dillierence being that there is mounted in this housing but a. single latch 19C for engaging the catch '21 when the switch blade is in cngagement with the contact jaws 13, ln this construction the latch 190isolsnbstantially the conformation described above vfor the latch 19, and this latch is pivotally supported upon a rod 183. carried by the housing 17H, so that the. operation ot the latch 19e is substantially the saine as described above for the latch 1S). With this construction a spring 27 is employed. to hold the latch normally in its engaging position, and this spring is preferably secnred'to the casing by rivets, as indicated, or by seine similar fastening' in ans. The casing is pre lli Bti

narrates the spring from getting out of place., and

prevents the insertion ot foreign matter into the casing and also gives the casing a better appearance than as though the said wall were notpresent. lin this construction the catch 24a is substantially the same as the catchQhand is similarly mounted between.

the contact jaws.

ln the modified construction shown in Fig.

i', the switch isot the single-throw type, andthe switch blade l0b has secured to its tree end a casing 17h similar to the casing i7,

in this construction the latch 19fis some? what differently conformed, in that .the pivot rod 18h 'supporting said latch andentending between opposite walls otv the cas ing 17h is located a considerable distance from the center line of the casing andswitch blade away from the hook portion 19g of the latch. ln this manner a maximum length ot latch between the pivot rod 18b and hook 19g is secured, so that the necessary amount ot motion ot' the hook may be had with a minimum amount of' motion of the operating tool. This construction also permits oit the catch 24h being of less-height, since the amount ot metal between the switch blade and the hook may be reduced to merely that required for mechanical strength to positively hold the switch in its closed position, whereas with the construction shown lin Figs. 2 and 5 a greater width is required to secure the same throw -of the hook oit' the 'latch for a given amount of motion lof the operating tool. `With the exception noted.7 the catch 24h is similar to the catches 24 and 241 described above, and is similarly mounted between the contact jaws 13b. With this construction a spring 27b is employed .to normally hold the latch lQf in its engaging po sition, this spring being somewhat did'en ently shaped than the spring shown in Fig. 5 to accommodate itself to the different conformation ot' latch, but in other respects the operation of the spring and its manner oi' support are substantially the same as for the spring 27a shown in Fig. 5. 4

ln the vconstruction shown in Fig. 9, the jaws 33 and 34 are engaged by the end/connectors 35 and 36 of a tubular fuse 37, the connector being pivotally secu-red to the jaw 33 at 38,' and the connector 36 being provided with locking mechanism con tained in the casing 39 for holding the connector 36 in position in the jaw 34e', which iocking mechanism may either be Aof the construction vabove described or that shown in Figs. l() or ll, as desired.

ln the drawings the construction ot locking mechanism in the casing 89'is assumed to be that shown in Fig. 10. rllhe jawsBS and 2id-are mounted upon supporting clamps d0 and 4h, which` in turn, are supported by the outer ends ofthe high-tension insulators d2 and d3, these insulators being, in turn, secured 1n any suitable manner to a desired support. rlthe operation of moving the fuse finto orout of engagement with the aw 34 and the accompanying operation ot the loclring mechanisr'nl is similar to that above described, and as tar as this operation is concerned the structureis in elect a switch. ln view lot this, l desire to have it understood that where the termv switch blade is used in the claims limean eithera simple switch blade as shown in Fig. l, or any other simii lar construction in which the ends of a circuit-connecting member engage contact jaws with which it is desirable to'positively hold the member in circuit-closing engagement.

As a result of the' construction shown in Fig. 9, when it is necessary to replace the fuse 37 the fuse is moved from engagement with the contact jaw 34 in substantially the manner that the switch blade 10V above described is opened, and the new fuse may be inserted in the connecting terminals 35 and 36 by loosening the clamping screws indi cated, after which the fuse and connector 36 may be moved so as to engage the Contact 'jaw 3st and bring the parts otthe locking mechanism into their engaging position.

his shown in Fig. 10, the locking mechas nism consists ot a latch del; and catch l5 similar to the latch and catch shown in Fig. '71', the principal difference being that a helical spring 46 is connected at one end to the outer end of the operating member of the-latch, while the other end of said spring is connected to a rod 47 extending between the 4 side walls of the casing. As a result of this construction, when the latch is operated the spring 46 is lengthened, and, being a tension spring, it tends at all times to hold the latch in 'its locking position. lWhile the flat spring. above' described gives `very good, results, j among .thel advantages of helical springs arranged as described may be mentioned complete inaccessibility from the outsidev of the casing .sothat it is impossible t0 tamper with them, and greater uniformity of operation. A guard wall 48 extends completely around the opening 49 through the isc'y casing for the reception of the operating tool, except that portion ot' the opening through which the operating' member mu'st project to secure proper operation of the latch.

lln the modified construction shown in Fig. 1l, the locking mechanism is substantially the same, with the exception that the spring t5 is located between the opening 49 and the pivot ot the latch ett, instead ot having theopeniiig t9 between the latch et and the spring 4G, as indicated in Fig. 10. ln this construction the lower end ot the spring is secured to the operating memberv operating members ot the latches are eX-,

tended beyond the opening 54: for receiving the operating tool and at their ends aie engaged by the ends ot a helical spring 55, as a result of which the tension of the spring tends at all times to hold each latch in ,its locking position. rfhe operation ot' the latches 50 and 51 is similar to that described in connection with Figs. 1 and 2 tor the latches 19 and 20, and the advantages above referred to for the helical spring arrangement are secured by the construction shown in Fig. 12 over that shown aiiddescribcd in connection with the flat spring arrangement in Fig. 2. Guard walls 56 are provided along the sides of the Iopening 54- to prevent access to the interior of the casing through said opening.

As a result of the construction described, it will be seen that I have provided a locking mechanism for switches of this kind in which the number of parts is reduced to a minimum, there being but t-wo parts for each* lock, to-wit, the latch and the spring asso-' ciated therewith, and that for the doublethrow switch there are but three parts, towit, the two latches and the common spring for holding the'latches in their engaging position. rlhus the operation of the-lock is made direct and posit-ive, and the construc-V tion is inexpensive to manufacture.

lWhile l have described above a single switch blade as equipped with my improved 'locking devices, it will be understood that the locking mechanism is equally applicable' to a double-pole switch construction, and

that it is immaterial whether a single switch blade or a plurality of blades is employed.

By the term contact jaw as used in the claims, it will be understood that l mean any form of contact adapted to engage lthe switch blade for closing a circuit whether said contact comprises one or more slotted or unslotted plates or any other equivalent construction; and by the term operating member as used in the claims I mean the part of the latch, as for example the part 19?, directly engaged by an external operating means, as for example the operating rod 22.

W'hile l have shown my invention in the mistico particular embodiments above described, .l

do not, however, limit myselt to these arrangements, as l may employ any equivalents thereo't within the scope ot the appended claims in carrying-out my invention.

lVhat I claim is:

1. In a switching mechanism, the combination oi a pivotcd switch blade having two operative positions, two contact jaws, one tor engagement wit-li* said blade in each oper- 'ative position, a catch associated with each jaw, a casing carried by the end ot said blade, two latches pivotally inoi'inted in said casing, one ttor engagement with each catch, each hitch having an operating lneniber rigidly associatcd therewith, and a helical spring secured at its ends to said operating members tor holding said latches in position to engage said catches.

'2. An electric switch comprising a pair ot posts, a. switch blade pivotally connected to one of the posts, a catch lug adjacent the other post, switch jaws adjacent said catch lug, a bracket secured to the blade, and a hook pivotally connected to thc'brackct, said l` bracket being at such distance 'from the pivot of the blade as to cause the hook to co-act with the catch lug when the, blade is closed, said bracket having an eye to be engaged by an operating implement1 and the hook having an. ear overlapping said eye.

3. An electric switch comprising a pair of posts', a switch blade pivotally connected to one of the posts, a catch lug adjacent the other post, switch jaws adjacent said catch lug, a bracket secured to the blade, and a hook pivotally connected to the bracket, said bracket being at such distance trom the pivot ot' the blade as to cause the hook to co-act with the catch lug whenthe blade is closed, said bracket having an opening for receiving an operating implement, 'and the hook having an ear overlapping said opening, and a spring tending to hold said hook inits cngaging position and said ear in its overlapping position.

t An electric switch comprising apair ot' posts, a switch blade pivotally connected to one ot the posts, a catch `lug adjacent the other post. switch jaws adjacent said catch lug, a bracket secured to the blade, and a hook pivotally connected to the bracket, said bracket being at such distance 'from the .pivot et thel blade as to cause the hook to co-act with the catch .lug when the blade is closed, said bracket comprising a casing for containing said hook and provided with openings throughits opposite walls toi' receiving an operating implement, and said hook having an ear located between said walls and overlapping said openings.

5. An electric switch comprisil g a pair of posts, a switch blade pivotallv connected to one of the posts, a catch lug adjacent the 'other post, switch jaws adjacent said catch taranto lug, a bracket secured to the blade, and a hook pivotally connectedto the bracket, said bracket being at such distance from the pivot of the blade as to cause 'the hook to co-act with the catch lug when the blade is closed, ysaid bracket having an opening for receiving an operating implement, and said hook having an ear overlapping said opening, and devices for mounting said catch lug so that it maybe moved longitudinally of said blade-to did'erent operative positions. 6. Ain electric switch comprising three posts located in substantially the same plane, a switch blade pivotally'connected tol one ot said posts, a catch lug adjacent each ot the otherposts, switch jaws adjacent each oisaid catch lugs, a bracket secured to the blade, and two hooks pivotal-ly connected to the bracket, 'said bracket being at such a .n distance fromA the pivot of the lblade as to to hold both hooks in cause each hook to co-act with va catch lug when the blade is vclosed in either of its operative positions,'said bracket having an opening for receiving an operating imple` ment, and each hook having an ear over-A la ping said opening.A

g. An electric switch comprising three posts located in substantially the same plane,

a switch blade pivotally` connected to'one 0of said posts, a catch lug adjacentA cachot the other posts, switch jawsadjacent each of said catch lugs, a bracket secured lto the blade, and two hooks pivotally connected to the bracket, said bracket being at such a distance from the pivot of the blade as 4to cause each hook to coeact'with ,a catch lng` when the blade is closed in either ot its operative positions, said bracket having an. opening for receiving an'foperating imple ment, and each hook havingan ear over#` lapping said opening, and a spring tendingposition to co-act with said catch lugs. l

8. Anfelectric switch comprising three posts located in substantially the same plane, a switch blade pivotally connected to one of said posts, a catch lug 'adjacent each ot the other posts, switch jaws adjacent each/ ot said catch lugs, a bracket secured to the blade, and two hooks pivotally connected to the bracket, said bracket being at such a distance from the pivot of the blade as to cause each hook to co-act with a catch lug when the blade is closed in either offits operative positions, said bracket having an opening `torreceiving an operating implement, and each hook having an earoverlapping said opening, each hook forming a` part of the pivot bearing ot the other hook.

9. An electric switch comprising three.

blade, and twohooks pivotally connected to.

the bracket, said bracket being at such a distance from the pivot of the blade as v.to canse each hook to co-act with a catch lug .when the blade is closed in either of its operative positions, said bracket comprising a casing for containing said hooks and provided with openings through its opposite` walls for receiving an operating implement, and each ot said hooks having an eart'located between said walls and overlapping said openings.

- l0. An electric switch comprising a pair of posts, a switch blade pivotally connected .to one vof the posts, a catch lug mounted adjacent the other post, switch jaws adjacent said catch lug, a bracket carried by the blade, and a hook pivotally connected to the bracket, said bracket being at such distance from the pivot ot the blade as* to v cause .the hook to coact with the catch lug when the blade is closed, said bracket having an o pening tor receiving an operating implement and the hook having an ear overlapping said opening.

1l. An electric switch comprising three posts located in substantially the same p1ane,a switch blade pivotally connected to one of said posts, a catch lu adjacent each of the other posts,l switch jaws adjacent each of said catch lugs, a bracket secured to the blade, and two hooks pivotally connected to the bracket, said bracket being atsuch a-distance v:trom the .pivot of the blade as to cause each hook to co-act with a catch lug when the blade is closed in either of its operative positions, said bracket having an opening tor receiving an operating implement, and each hook having an ear overlapping said opening, the pivots ot said hooks being located in a common axis eX- tending through the intersection of the center line ot said blade and a line through the JEDSN SESSIONS. 

